Improved Emission Characteristics Research Articles

Experimental investigation on diesel engine performance and emission characteristics using waste cooking oil blended with diesel as biodiesel fuel

Biodiesel production from waste cooking oil is a potential feedstock to alternative fuel sources. Produced alternative fuel sources were to have a strong emphasis on energy efficiency to substitute the declining world supply of fossil fuels while also improving emission characteristics in diesel engine applications. The development of industrialization and mechanization causes increased fossil fuel consumption and its usage. This study aimed at an experimental investigation of biodiesel blended fuel combustion efficiency for single-cylinder diesel engines under varying engine loads at constant engine speed 1500 rpm. The transesterification process was used to produce biodiesel from waste cooking oil using NaOH as catalysts. Biodiesel reaction takes place with oil to methanol ratio of 6:1 at 60 °C reaction temperature for 90 min with 600 rpm stirring speed while 90% yield gained. Eight sample biodiesel blends were prepared with percentage value B5%, B10%, B15%, B20%, B25%, B30%, B35%, B40% v/v and B100% to investigate the effect of biodiesels on engine performances. The experimental result reveals that the mixed biodiesel blends have lower average value in terms of brake torque, brake power, and brake thermal efficiency than diesel fuels as a percentage of 16.79%, 4.08%, and 27.9% respectively. In addition, the average BSFC of biodiesel blends was increased by 4.8% than baseline diesel fuel. Related to exhaust gases emission test results were shows that the average CO and HC emissions decreased by 52.2% and 60% with increasing loads and blends and the increment of CO2 and NOx by 28.1% and 45.4% respectively than baseline fuel with increasing blends and loads. Biodiesel derived from waste cooking oil was less costly and environmentally friendly and viable to substitute petro-diesel.

Hot Exciton versus Hot Exciplex TADF Mechanism – Effect of the Donor‐Acceptor Functionalization Pattern on Anthracene‐based Emitters

Hot exciton emitters based on 9,10‐substituted anthracenes are a well‐investigated class of molecules featuring thermally activated delayed fluorescence (TADF). TADF converts triplet excitons into singlet excitons and improve the internal quantum efficiency of electroluminescent devices to performance beyond the limit of spin‐statistics of conventional emitters. In this paper, we compare different 1,8‐functionalized donor/acceptor‐substituted anthracenes and compare these to established 9,10‐functionalized hot exciton emitters. Interestingly, our new 1,8‐substituted anthracenes make use of a beneficial hot exciplex pathway, resulting in improved emission characteristics and higher photoluminescence quantum yield.

Impact of Fuel Hydrogenation and Fuel Additives on Dual Biodiesel Mixture for Improving Combustion and Emission Characteristics in Compression Ignition Engine

Impact of Fuel Hydrogenation and Fuel Additives on Dual Biodiesel Mixture for Improving Combustion and Emission Characteristics in Compression Ignition Engine

Densification effect on field emission characteristics of CNT film emitters for electron emission devices

Field electron emission characteristics of the carbon nanotube (CNT) film emitters were investigated according to densification conditions such as nitric acid, acetic acid, and salicylic acid. The emission performance of the CNT film emitters was strongly affected by the densification conditions. Salicylic acid exhibits the best field electron emission properties of the CNT film emitters, followed by nitric acid and acetic acid. The efficient densification of the CNT film emitter by salicylic acid is caused by the role of polarity and p orbitals, nitric acid by hydrogen ions, and acetic acid by weak polarity. After the densification with salicylic acid, the turn-on field of the CNT film emitter decreases from 1.94 V μm−1 to 1.86 V μm−1, the threshold field decreases from 3.41 V μm−1 to 2.95 V μm−1, the emission current significantly increases from 20.92 mA to 43.98 mA, and the degradation rate from the long-term emission stability decreases from 49.9% to 21%. The improved emission characteristics are attributed to the increased emission sites at the CNT film and the increased electrical conductivity of the CNT film. The densification is a useful way to enhance the field electron emission properties of CNT film emitters.

Large scale fabrication of GaN nanorods template and characterization of MOCVD grown InGaN/GaN quantum wells on [formula omitted] plane of GaN nanorods

Gallium nitride (GaN) based low-dimensional optoelectronic devices offer distinct advantages over bulk counterparts owing to enhanced surface-to-volume ratio and better strain management. Among these devices, InGaN/GaN multi-quantum wells (MQWs) based on nanostructured GaN have garnered attention due to tunable bandgap along with reduced size for its possible integration into display technology. However, to mitigate the effects of polarization induced by polar planes of GaN, such as quantum confined stark effect, researchers are exploring the growth of MQWs on non-polar planes as a practical approach to improve emission characteristics and device performance. In this work, we present the fabrication of GaN nanorods (NRs) using a two-step etching method, followed by the growth of core-shell InGaN/GaN MQWs on the exposed non-polar {101‾0} sidewalls of GaN NRs. Our metrological studies confirmed the successful growth of InGaN/GaN MQWs on the non-polar sidewalls of strain-relaxed core GaN NRs. Furthermore, power-dependent luminescence study showed emission characteristics with absence of polarization-induced effects. Cathodoluminescence study validated the emission characteristics of InGaN/GaN MQWs grown on the exposed sidewalls of the GaN NRs.

Field electron emission behavior of pristine and Au nanoparticles decorated Sb2Te3-rGO heterostructure emitters

A facile one-pot hydrothermal method was used to synthesize pristine Sb2Te3 and its heterostructure with reduced graphene oxide (rGO). A novel approach dealing with high energy (6 MeV) electron irradiation has been efficiently used for synthesis of gold nanoparticles (Au- NPs) and their in-situ decoration on Sb2Te3-rGO heterostructure. From an application point of view, we have investigated the field electron emission characteristics of pristine Sb2Te3 and Sb2Te3-rGO heterostructures, with and without Au-NPs decoration. The Au-NPs decorated Sb2Te3-rGO heterostructure emitter showed enhanced electron emission behavior in terms of reduced value of turn-on field, delivery of large emission current density (∼1171 µA/cm2) at relatively lower applied field (∼3.1 V/µm), and excellent emission stability. The improvement in emission characteristics upon decoration of Au-NPs is attributed to noticeable increase in the number of emission sites, higher value of field enhancement factor (β = 4562), and betterment in the electronic properties due to Au-NPs-Sb2Te3-rGO interface effects. The obtained results suggest that Au-NPs decorated Sb2Te3-rGO heterostructure emitter has potential towards practical applications in various vacuum microelectronic devices. Furthermore, the present approach dealing with high energy electron irradiation for synthesis and in-situ decoration of nanoparticles can extended to other inorganic heterostructures towards improving their functionality.

Zn-Doped P-Type InAs Nanocrystal Quantum Dots.

Doped heavy metal-free III-V semiconductor nanocrystal quantum dots (QDs) are of great interest both from the fundamental aspects of doping in highly confined structures, and from the applicative side of utilizing such building blocks in the fabrication of p-n homojunction devices. InAs nanocrystals (NCs), that are of particular relevance for short-wave IR detection and emission applications, manifest heavy n-type character poising a challenge for their transition to p-type behavior. The p-type doping of InAs NCs is presented with Zn - enabling control over the charge carrier type in InAs QDs field effect transistors. The post-synthesis doping reaction mechanism is studied for Zn precursors with varying reactivity. Successful p-type doping is achieved by the more reactive precursor, diethylzinc. Substitutional doping by Zn2+ replacing In3+ is established by X-ray absorption spectroscopy analysis. Furthermore, enhanced near infraredphotoluminescence is observed due to surface passivation by Zn as indicated from elemental mapping utilizing high-resolution electron microscopy corroborated by X-ray photoelectron spectroscopy study. The demonstrated ability to control the carrier type, along with the improved emission characteristics, paves the way towards fabrication of optoelectronic devices active in the short-wave infrared region utilizing heavy-metal free nanocrystal building blocks.

Interpretation of the performance and emission characteristics of a CI engine running on ethanol-butanol diesel blends using an optimisation model

Every nation is attempting to minimise pollution in a variety of ways as government's upcoming laws and bills on emissions mitigation have sped up engine development. Our research's goal is to investigate alternative optimisation models for emission and performance to find the optimal ethanol-butanol diesel blends. This research looked at CO, CO2, NOx, and HC levels as emission parameters. Minor variations in the performance metrics like brake thermal efficiency (BTE), brake power, torque, and mechanical efficiency were recorded. It was evident from the graphs that the performance characteristics were slightly higher than neat diesel and except for the amount of unburned hydrocarbon, there has been a substantial improvement in emission characteristics. The goal of optimisation is to find the best alcohol diesel mix percentage that can be utilised in a diesel engine. The ideal mix is chosen based on the desirability value derived from the optimisation data.

Experimental investigation on performance and emissions of a VCR engine fuelled by biodiesel/diesel blends

As the global market for fuel increased exponentially, there was a dramatic decline of fossil fuels which led to an extensive discovery of biodiesel as an alternate fuel for diesel engines. The current research investigates the influence of neem oil biodiesel-diesel blends on the performance and emission characteristics of a variable compression ratio (VCR) engine. The experiments were conducted with B5, B10, B15, B20 and B25 blends of neem oil biodiesel in a VCR engine at a constant speed of 1500 rpm, varying the load and at compression ratios (CRs) of 16:1,17:1 and 18:1. The impact of increasing the CRs on the performance and emissions of neem oil biodiesel blends has been thoroughly investigated in this study. The BTE, SFC and EGT improved with increase in CR. The fuel samples were evaluated and compared to conventional diesel, which had great improvement in emission characteristics. The outcomes of this study show that neem oil biodiesel blends may be utilized as a diesel alternative in diesel engines without requiring any engine changes. CR 18:1 may be justified as the best optimal CR for any fuel.

Potential of Oxymethylene Dimethyl Ether for a Diesel Engine Improving Emission and Combustion Characteristics

Potential of Oxymethylene Dimethyl Ether for a Diesel Engine Improving Emission and Combustion Characteristics

Feasibility of Biofuels as a Substitute to Conventional Fuels in IC Engines for Mass Transport and Distributed Power Generation

Depletion of petroleum based fuels has been a lot of concern among thegovernments and researchers around the world. Usage of biofuels in placeof the conventional fuels is showing rapid growth because of the favourablecharacteristics like better performance and time improved emission char-acteristics. Present paper discusses about different available biofuels andtheir effectiveness in replacing fossil fuels and also how they affect thetechnological growth. Different works are compared to bring out the actualscenario with respect to the performance, emission, availability, productionand preparation methods. It is observed that much effort is made by the stakeholders in order to see biofuels as a viable alternative and as a future fuel forinternal combustion engines. Performance improves slightly with the usageof biofuels and reduced emission characteristics may be logical to observe.But it may not be appreciable, considering the series of production processesinvolved. It still requires lot of time to commercialize and produce biofuels in mass. Also, there have been constraints like the availability of raw materialsfor the same. It is concluded that biofuels do play significant role in the daysto come provided there is much more effort from researchers to simplify thetechnology in making biofuel as sustainable and cost effective with at leastcomparable performance.

Performance and emission characteristics of a diesel engine using diesel-raw Jatropha oil blends

ABSTRACTThe usage rate of fossil fuels increases exponentially every day at an alarming rate, however, it must be noted that these fuels are limited in nature. Since the usage rate is much greater than the replenishment, it could be stated that it is the time for technologies to adapt to other sources of energy. Hence this paper emphasis on the possibility of substituting commercial diesel with blends of raw Jatropha oil and diesel to enable current automobiles to adapt to a blended fuel which when studied to more depth could eliminate the need for fossil fuels by completely replacing them with non-edible vegetable oils. This study focuses on the effects of mixing of raw Jatropha oil and diesel at various proportions (B10, B20, B30) on diesel engine operations. The objective of this work is to find the maximum replacement of diesel fuel with raw Jatropha oil-based better performance and improved emission characteristics. The test fuel results were compared with the engine running on diesel fuel. The outcomes of experiments reveal that B10 blend fuel gave better result in terms of improved performance and reduced emission levels.

Modeling of an Impact of Thin Insulating Film on the Electrode Surface on Discharge Ignition in Mercury Illuminating Lamps at Low Ambient Temperatures

The mixture of argon and mercury vapor with temperature-dependent composition is used as the background gas in different types of gas discharge illuminating lamps. The aim of this work was to develop a model of the low-current discharge in an argon-mercury mixture at presence of a thin insulating film on the cathode and to investigate the influence of film on the discharge ignition voltage at low ambient temperatures. When discharge modeling, we used the obtained earlier expression which describes dependence of the mixture ionization coefficient on temperature. When there was a thin insulating film on the cathode the model took into account that positive charges are accumulated on its surface during the discharge. They generate an electric field in the film sufficient for the field emission of electrons from the metal substrate of the electrode into the insulator and some of them can overcome the potential barrier at the film outer boundary and go out in the discharge volume improving emission characteristics of the cathode.Calculations showed that at a temperature decrease the electric field strengthes in the discharge gap and the voltage in it are increased due to reduction of the saturated mercury vapor density in the mixture followed by the decrease of its ionization coefficient. Existence of a thin insulating film on the cathode surface results in an increase of the cathode effective secondary electron emission yield which compensates the reduction of the mixture ionization coefficient value.The results of discharge characteristics modeling demonstrate that in case of the cathode with an insulating film the discharge ignition becomes possible at a lower inter-electrode voltage. This ensures outdoor mercury lamp turning on at a reduced supply voltage and increases its reliability under low ambient temperatures.

Potentials of OME/diesel blends for stationary power production – Improving emission characteristics of a diesel CHP unit

Polyoxymethylene dimethyl ethers (OME) with the chemical structure H3CO[-CH2-O-]nCH3 are a promising alternative fuel for improving emissions characteristics of internal combustion engines and can be produced from renewable sources. Especially the PM-NOx trade-off of diesel engines is known to be effectively mitigated by blending OME with diesel. Recent investigations concentrate on the utilization OME fuels in mobile applications. However, these fuels could also be of interest for stationary engines used in gensets and combined heat and power units (CHP). In the present paper we examine the use of OME2-6/diesel blends up to 50% in a CHP unit in practical operation equipped with a heavy-duty six-cylinder engine, applying different load conditions and engine settings, including Exhaust Gas Recirculation (EGR) and the adjustment of injection timings. No negative effects on the performance and efficiency of the engine were observed with the OME blends. Particulate Matter (PM) and Particle Number (PN) decreased significantly with increasing content of OME in the blend, especially when EGR was applied. The Particle Number Size Distribution (PNSD) showed a trend towards smaller particle sizes. NOx rose slightly in direct comparison, but this was by far overcompensated by the reduction achieved through EGR. The results indicate that OME fuels in combination with EGR could become a feasible option for emission reduction in diesel gensets and CHP units due to the very low particle emissions, which mitigate the risk of EGR cooler fouling.

Metal‐based additives “acetylferrocene and ruthenium polypyridyl complex” to improve performance and emission characteristics of ci engine

Metal‐based fuel additives have been promising alternative choice to improve diesel engine performance and emission characteristics. Many studies have been performed on use of metal‐based fuel additives such as magnesium, platinum, titanium, and cerium in diesel engine. Unlike conventional metal‐based additives, Acetylferrocene and Ruthenium polypyridyl complex may be alternative metal‐based additives for diesel. This study intends to investigate performance and emission variations of a diesel engine powered by diesel blended with Acetylferrocene and Ruthenium polypyridyl complex additives. In accordance with this purpose, a single cylinder, direct injection diesel engine was used to test these alternative metal additives. Results showed that Acetylferrocene and Ruthenium polypyridyl complex were effective to improve emission characteristics without causing degradation in performance. CO and Soot emissions were showed decrease up to 40% and 32%, respectively, and the fuel consumption characteristic of engine was improved with additives. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13146, 2019

Bio-ethanol additive effect on direct injection diesel engine performance, emission and combustion characteristics – an experimental examination

ABSTRACT The present investigation explores the effect of dairy scum oil methyl ester (DSOME) blends and ethanol additive on TV1 Kirloskar diesel engine performance, combustion and emission characteristics. From the experimental study, it is concluded that DSOME-B20 (20% dairy scum biodiesel + 80% diesel) has shown appreciable performance and lower HC and CO emissions among all other blends. Hence DSOME-B20 is optimised as best fuel blend and it is carried for further investigations to study the effect of bio-ethanol additive on diesel engine performance. From the study it apparent that diesel engine operated with ethanol additive and 20% dairy scum biodiesel blended fuels shown the satisfactorily improved emission characteristics when compared to petroleum diesel fuel operation. Finally, from the experimental investigation, it concludes that addition of ethanol shown the slightly higher HC, CO emission and improved BTE, BSFC, NOx and CO2 than sole B20 biodiesel blend. Among all three (3%, 6% and 9%) ethanol additive ratios, E6% (6%-ethanol with B20) ethanol additive exhibits slightly better BTE, BSFC, cylinder pressure and heat release rate hence 6% ethanol additive with B20 biodiesel blend would furnish beneficial effects in the diesel engine.

Abstract 599: Exposure to Biodiesel Exhaust Triggers Atherosclerotic Plaque Destabilisation through Increased Apoptosis of Vascular Smooth Muscle Cells in the Arterial Vessel Wall

Introduction: Long-term exposure to air pollutants increases cardiovascular morbidity and mortality. Particulate matter (PM) derived from diesel exhaust has been documented to be pro-atherogenic in animal studies. Biodiesels are widely introduced as new fuels with improved emission characteristics. However, biodiesel contains relatively more polycyclic aromatic carbohydrates (PAH) compared to diesel. Therefore, we hypothesise that exposure to biodiesel as compared to diesel exhaust results in increased atherosclerosis. Methods and Results: In a carotid cuff atherosclerosis model, the effects of exposure to exhaust PM of biodiesel vs. diesel PM vs. saline (control) on atherosclerosis were evaluated. Both common carotid arteries in LDLR -/- mice were cuffed at week 2 in the course of an 8-week high-fat diet regimen. All mice were intratracheally instilled with saline, PM biodiesel or biodiesel once-weekly for 5 times. Immunohistochemistry and primary human vascular smooth muscle cells (hVSMC) were used for evaluation. Results: Exposure to both biodiesel and diesel didn’t exacerbate atherosclerosis development, however, biodiesel affected plaque composition towards a more vulnerable phenotype as compared to diesel with decreased total collagen content and hVSMC (respectively -100%, p=0.09 and -339%, p<0.01 and tend to increase necrotic core volumes (37.5% vs 28.9 % p=0.2). Exposure to biodiesel PM triggered loss of hVSMC in tunica-media, strongly correlating with apoptosis in the vessel wall (Pearson r=0.7, p<0.01). These findings were supported by dose-dependent apoptosis of hVSMCs upon 2-hour PAH treatment. Conclusions: This study demonstrates that exposure to biodiesel exhaust PM dramatically modulates atherosclerotic plaque composition, resulting in an unstable plaque phenotype through enhanced pro-apoptotic mechanisms.

Distinct light emission from two-dimensional electron gas at a lattice-matched InAlN/AlGaN heterointerface

We report on distinct light emission from two-dimensional electron gas (2DEG) at a lattice-matched (LM) In0.12Al0.88N/Al0.21Ga0.79N heterointerface. The recombination between the electrons in the 2DEG in the ground state E1 and photoexcited holes in the Al0.21Ga0.79N layer was identified. In contrast to GaN channel-based heterostructures (HSs), larger activation energy of the 2DEG-related emission from LM In0.12Al0.88N/Al0.21Ga0.79N HS was obtained to be approximately 17 meV, which enables the distinguished 2DEG photoluminescence (PL) peak to be more thermally stable. Moreover, the existence of the 2DEG accelerates the reduction of the PL lifetime of the emission from Al0.21Ga0.79N. Compared to the general 2DEG PL feature with a broad recombination band in GaN channel-based HSs, the improved emission characteristics of the 2DEG in the In0.12Al0.88N/Al0.21Ga0.79N HS were attributed to electron localization in a deep triangular potential well, large 2DEG density induced by the In0.12Al0.88N layer, and the improvement of the interfacial crystal quality due to the lattice match between In0.12Al0.88N and Al0.21Ga0.79N layers. These findings provide important insight into understanding the InAlN-based HSs and will be potentially useful to advance the electronic and photonic applications for group-III nitrides.

Effect of Fuel Injection Pressure on Performance and Emission Characteristics of DI- CI Engine with Shea Olein Biodiesel

The use of diesel engines day by day increased because of their low fuel consumption and high efficiencies. Several attempts were made for search of alternative fuels due to increased environmental pollution and exhaustion of conventional fossil fuels and succeeded in the development of Biodiesel as an alternative fuel. An attempt was made on DI- CI engine using shea olein methyl ester blended with diesel in various proportions to study the engine performance and emissions at different injection pressures. The tests were conducted at constant load at different injection pressures (190, 200, 210, 220, 230 bars). In the present work performance characteristics like Brake thermal efficiency, Specific fuel consumption, exhaust gas temperature and emission characteristics like CO, NOX, HC had been investigated. From the results it is observed that 210 bar injection pressure causes better performance and improved emission characteristics, for all the fuel blends.

Impact assessment of Ethanol as Fuel for Engine operation

For past decades, excessive extraction of fossil fuels to cater the energy demands of ever rising population and industrial growth has resulted in situation to look for alternative resources of energy. In addition, endless use of petroleum based fuels like diesel have caused in environmental degradation. Different alternative fuels like biodiesel, alcohols fuels (ethanol, butanol, pentanol), hydrogen, Liquefied Petroleum Gas (LPG), methane, and Compressed Natural Gas (CNG) have caught the attention of researchers around the world due to similar performance and improved emission characteristics compared to fossil diesel.This work dealsabout investigation of physical and chemical properties of ethanol & diesel blends .The focus is around the properties which impact the infusion properties and motor attributes, ethanol and diesel fuel mixes are measured by prerequisites for the diesel fuel. The result shows that 15% ethanol diesel fuel mixes utilizing ethanol as a transportation fuel could display preferable environment execution over ordinary gas in the terms of an Earth-wide temperature boost and fossil fuel utilization. The result also shows that HC and CO emissions are low in case 15% ethanol/diesel blends as compared to diesel.